When using System.delete ensure module is reexecuted

[guybedford]

Apparently this works for dynamic but not declarative.

[wclr]

Right,

System.delete('my/module')
System.define('my/module', ...) // System.import as well

doesn't work as expected, module is not re-executed.

[guybedford]

Completed.

[wclr]

Great. It is not published yet? (available via jspm)

[guybedford]

It's published, but not in SystemJS yet.

Quick question (and I asked this a few months ago but I'm curious if anything's changed): When deleting and redefining or reimporting modules, do any modules that depend on the module need to be manually reloaded? If so, what's the best way to go about this?

[wclr]

@timbur no, you should manually reload dependendencies tree (or needed modules) if you want correct reload.

Got it, thanks. I'll paste the code I hacked together to do it, if anyone is interested. There's probably a more efficient way but I just went with the first thing I thought of.

(Requires System.trace = true.)

function reload(path, code) {
  var reloaded = {};
  var loads = System.loads;
  var names = Object.keys(loads);

  names.forEach(function (name) {
    var options = loads[name];

    if (options && options.address && options.address.indexOf(path) > -1) {
      reloaded[name] = true;
      doReload(options, code);
      console.info('Reloaded: '+name);
      reloadDependents(name, loads, names, reloaded);
    }
  });

  if (!Object.keys(reloaded).length) {
    throw new Error('Unable to find module for "'+path+'"!');
  }
}

function reloadDependents (moduleName, loads, names, reloaded) {
  names.forEach(function (name) {
    var options = loads[name];
    var depMap = options && options.depMap;

    if (moduleName !== name && !reloaded[name] && depMap && isDependent(moduleName, depMap)) {
      reloaded[name] = true;
      doReload(options, options.source);
      console.info('Reloaded dependent: '+name);
      reloadDependents(name, loads, names, reloaded);
    }
  });
}

function isDependent (moduleName, depMap) {
  if (depMap[moduleName] !== undefined) {
    return true;
  }

  for (var dep in depMap) {
    if (depMap[dep] === moduleName) {
      return true;
    }
  }

  return false;
}

function doReload (oldOptions, code) {
  var name = oldOptions.name;
  var options = {};

  try {
    options.address = oldOptions.address;
    options.metadata = {};
    options.metadata.plugin = oldOptions.metadata.plugin;

    System.delete(name);
    System.define(name, code, options);
  } catch (err) {
    System.delete(name);
    System.define(name, oldOptions.source, oldOptions);

    throw new Error(err);
  }
}

[wclr]

stealjs (loader based on System.js) can do such hot reload for modues (thought I din't use it), you can look in the code
https://github.com/stealjs/live-reload/blob/master/live.js